The Planox stereoscopes were manufactured by Établissements A. Plocq from Paris. The company was founded in 1895[1] by Alexandre Plocq[2] and was located at Rue de Center, Les Lilas. The online patent register provides a nice overview of the company’s history. The first patent is registered by Alexandre Plocq and dates from 1902[2]. A patent from 1926 is linked to Plocq Père et Fils (father and son)[3]. The patents from 1928 are registered by Alberic-Alfred Plocq, who continues his father’s company[4]. The last patent to his name dates back to 1958, proving that the company had a long history.
The company built both hand-held and table-top stereoscopes for 45x107mm, 6x13cm and 7x13cm glass stereoviews[1]. The Planox Stéréoscope Magnétique was introduced after the First World War[5] and has a characteristic design with an oblique backside that contains an opaque glass window that illuminates the slides. The front panel contains a copper plate in Art Nouveau style.
The eyepieces can be focused and the distance between the two eyepieces is adjustable. The set distance is visible on a copper plate in millimeters. The eyepieces can easily be removed for cleaning.
The front panel can be opened to place the slide-tray with stereoviews. A brief users instruction is visible on the inside. A slide-tray can contain twenty 6x13cm glass stereoviews. The Planox can also be used to view autochromes. Because of their thickness, a special slide-tray is needed that can store ten autochrome slides.
By pushing the operating lever down, a new stereoview is loaded. Most table-top stereoscopes use a mechanism that lifts the glass slide from below and places it in front of the eyepieces. The Planox pulls the stereoviews from above by using a magnetic pickup. Every stereoview should be provided with a little metal strip on top. The intention is to leave these strips, because changing them is cumbersome and could easily scratch the glass.
A slide index on the right side of the device shows which stereoview is displayed. If the operating lever is in down position and by turing the little knob 90 degrees clockwise, the slide-tray can be moved to every position.
References
- Plocq A. Stéréoscopes “Planox”, 1932 (pdf)
- Plocq, Alexandre. Perfectionnements aux appareils photographiques, patent FR327895, December 31, 1902 – via: data.inpi.fr
- Plocq Père et fils. Monture de plaque pour stéréoscopes et appareils similaires, patent FR616921, May 31, 1926 – via: data.inpi.fr
- Plocq, Alberic-Alfred. Stéréoscope, patent FR668116, June 21, 1928 – via: data.inpi.fr
- Wing, Paul. Stereoscopes: the first one hundred years, 1996. p.192